Wafer processing apparatus and wafer processing method using the same apparatus

ABSTRACT

A wafer processing apparatus is provided. The apparatus includes: a heating plate through which vacuum ports are formed; a plurality of temperature sensors; a heating device configured to heat the heating plate; first and second power supplies; temperature controllers to generate first and second feedback temperature control signals for controlling power output power supplies based on measurement values generated by the temperature sensors; an electronic pressure regulator configured to provide vacuum pressure for fixing a wafer to the plurality of vacuum ports; and a wafer chucking controller configured to control the electronic pressure regulator, and generate a feedback pressure control signal for controlling the electronic pressure regulator based on the first and second feedback temperature control signals.

CROSS-REFERENCE TO THE RELATED APPLICATION

This application claims priority from Korean Patent Application No.10-2019-0089220, filed on Jul. 23, 2019 in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein byreference in its entirety.

BACKGROUND

Methods and apparatuses consistent with embodiments of the presentapplication relate to a wafer processing apparatus and a waferprocessing method using the same.

Various processes, such as oxidation, photolithography, etching,thin-film deposition, metallization, electrical die sorting (EDS),packaging, etc., are performed on a wafer in order to manufacturesemiconductor devices. As the semiconductor devices are miniaturized,high precision control of conditions of the semiconductor processes isincreasingly required. In particular, in order to improve the yield rateof the semiconductor manufacturing processes, it is essential toidentify warpage of a wafer in each of the processes, determine thedegree of warpage, and realize uniform processing conditions to minimizethe warpage of the wafer.

SUMMARY

One or more embodiments provide a wafer processing apparatus foruniformly controlling a temperature of the entire wafer and a waferprocessing method using the wafer processing apparatus.

Embodiments are not limited to the objectives described above and otherobjectives which are not mentioned may be clearly understood by one ofordinary skill in the art from the descriptions below.

According to an aspect of an embodiment, there is provided a waferprocessing apparatus including: a heating plate through which aplurality of vacuum ports is formed, and a central region and an edgeregion surrounding the central region are defined; a plurality oftemperature sensors equipped in the heating plate; a heating deviceconfigured to heat the heating plate; a first power supply and a secondpower supply configured to provide operational power to differentportions of the heating device; a first temperature controllerconfigured to generate a first feedback temperature control signal forcontrolling power output of the first power supply based on a firstmeasurement value generated by the plurality of temperature sensors; asecond temperature controller configured to generate a second feedbacktemperature control signal for controlling power output of the secondpower supply based on a second measurement value generated by theplurality of temperature sensors; an electronic pressure regulatorconfigured to provide vacuum pressure for fixing a wafer disposed on theheating plate to the plurality of vacuum ports and regulate pressure ofthe plurality of vacuum ports; and a wafer chucking controllerconfigured to control the electronic pressure regulator, and generate afeedback pressure control signal for controlling the pressure of theelectronic pressure regulator based on the first feedback temperaturecontrol signal and the second feedback temperature control signal.

According to an aspect of an embodiment, there is provided a waferprocessing apparatus including: a heating plate through which aplurality of vacuum ports is formed, and a central region, an edgeregion surrounding the central region, and a middle region between thecentral region and the edge region are defined; a plurality oftemperature sensors configured to measure a temperature of the heatingplate; a heating device configured to heat the heating plate; a firstpower supply, a second power supply and a third power supply configuredto provide operational power to the heating device; a first temperaturecontroller configured to generate a first feedback temperature controlsignal for controlling a first power output of the first power supplybased on a first measurement value of the plurality of temperaturesensors; a second temperature controller configured to generate a secondfeedback temperature control signal for controlling a second poweroutput of the second power supply based on a second measurement value ofthe plurality of temperature sensors; a third temperature controllerconfigured to generate a third feedback temperature control signal forcontrolling a third power output of the third power supply based on athird measurement value of the plurality of temperature sensors; anelectronic pressure regulator configured to regulate pressure of theplurality of vacuum ports; and a wafer chucking controller configured tocontrol the electronic pressure regulator. The plurality of vacuum portsincludes: a plurality of first vacuum ports arranged in circularsymmetry with respect to the center of the heating plate; and aplurality of second vacuum ports arranged in circular symmetry withrespect to the center of the heating plate and farther from the centralregion of the heating plate than the plurality of first vacuum ports.The electronic pressure regulator includes: a first electronic pressureregulator configured to regulate pressure of the plurality of firstvacuum ports; and a second electronic pressure regulator configured toregulate pressure of the plurality of second vacuum ports. The waferchucking controller is further configured to generate a first feedbackpressure control signal and a second feedback pressure control signalconfigured to control, respectively, pressure of the first electronicpressure regulator and the second electronic pressure regulator based onthe first feedback temperature control signal, the second feedbacktemperature control signal and the third feedback temperature controlsignal.

According to an aspect of an embodiment, there is provided a waferprocessing apparatus including: a heating plate through which aplurality of vacuum ports is formed, and a central region and an edgeregion surrounding the central region are defined; a plurality oftemperature sensors configured to measure a temperature of the heatingplate; a heating device configured to heat the heating plate; a firstpower supply and a second power supply configured to provide operationalpower to the heating device; a first measuring device and a secondmeasuring device configured to measure a first power output of the firstpower supply and a second power output of the second power supply,respectively; a first temperature controller and a second temperaturecontroller configured to generate a first feedback temperature controlsignal and a second feedback temperature control signal configured tocontrol the first power output and the second power output based onmeasurement values of the plurality of temperature sensors; anelectronic pressure regulator configured to regulate pressure of theplurality of vacuum ports; and a wafer chucking controller configured tocontrol pressure of the electronic pressure regulator, and generate afeedback pressure control signal for controlling the pressure of theelectronic pressure regulator based on the first power output and thesecond power output.

According to an aspect of an embodiment, there is provided a waferprocessing method including: heating a heating plate, wherein aplurality of vacuum ports are formed through the heating plate andvacuum pressure is applied to the plurality of vacuum ports; loading awafer on the heating plate; controlling a heating device to heat theheating plate to a pre-set temperature and substantially maintain theheating plate at the pre-set temperature in correspondence to atemperature change of the heating plate due to the wafer being loaded onthe heating plate; identifying warpage of the wafer based on poweroutputs of the heating device; and regulating the vacuum pressure in theplurality of vacuum ports based on the warpage of the wafer.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages will be moreclearly understood from the following detailed description taken inconjunction with the accompanying drawings in which:

FIGS. 1A, 1B and 1C are a diagrams for describing a wafer processingapparatus according to embodiments;

FIGS. 2A, 2B and 2C are plan views for describing a heating plateaccording to embodiments;

FIG. 3 is a flowchart of a wafer processing method according toembodiments;

FIG. 4 is a graph showing a result of an experimental example fordescribing a wafer processing method according to embodiments;

FIG. 5 is a diagram for describing a wafer processing apparatusaccording to other embodiments;

FIG. 6 is a top view schematically illustrating a heating plate includedin a wafer processing apparatus according to example embodiments;

FIG. 7 is a flowchart of a wafer processing method according toembodiments;

FIGS. 8A and 8B are plan views showing a top surface of a heating platefor describing chucking of a wafer, according to embodiments;

FIG. 9 is a diagram for describing a wafer processing apparatusaccording to embodiments;

FIG. 10 is a flowchart of a wafer processing method according toembodiments;

FIG. 11 is a schematic perspective view for describing a bake apparatusaccording to embodiments; and

FIG. 12 is a block diagram of a system including a bake apparatusaccording to embodiments.

DETAILED DESCRIPTION

Hereinafter, embodiments will be described in detail by referring to theaccompanying drawings. Like reference numerals will be used for likereference components in the drawings, and repeated descriptions will notbe given. In the drawings hereinafter, a thickness or a size of each oflayers is exaggerated for convenience and clarity of description, andthus, actual shapes and ratios of the components may be slightlydifferent from the drawings. Expressions such as “at least one of,” whenpreceding a list of elements, modify the entire list of elements and donot modify the individual elements of the list. For example, theexpression, “at least one of a, b, and c,” should be understood asincluding only a, only b, only c, both a and b, both a and c, both b andc, or all of a, b, and c.

FIG. 1A is a diagram for describing a wafer processing apparatus 100 aaccording to embodiments.

Referring to FIG. 1A, the wafer processing apparatus 100 a may include aheating plate 110, a first temperature controller 121 and a secondtemperature controller 123, a first power supply 131 and a second powersupply 133, a wafer chucking controller 140, and an electronic pressureregulator 150. For example, the electronic pressure regulator 150 mayinclude an electronic air flow regulator.

A wafer W may be arranged on the heating plate 110. According to one ormore embodiments, the heating plate 110 may heat the wafer W to apre-set temperature. According to one or more embodiments, the heatingplate 110 may support and fix the wafer W and maintain the temperatureof the wafer W at a pre-set temperature, while various semiconductordevice manufacturing processes are performed on the wafer W.

The processes to be performed on the wafer W while the wafer W is loadedin the wafer processing apparatus 100 a and supported by the heatingplate 110, may include i) a thermal oxidation process for forming anoxide layer, ii) a lithography process including spin coating, exposure,and development, iii) a thin-film deposition process, and iv) a dry or awet etching process. That is, the heating plate 110 may be a chuckingdevice to support the wafer W and maintain the temperature of the waferW during semiconductor device manufacturing processes, where thetemperature of the wafer W has to be maintained at a pre-settemperature.

The thin-film deposition process to be performed on the wafer W may be,for example, any one of atomic layer deposition (ALD), chemical vapordeposition (CVD), plasma-enhanced CVD (PECVD), metal organic CVD(MOCVD), physical vapor deposition (PVD), reactive pulsed laserdeposition, molecular beam epitaxy, and DC magnetron sputtering.

The dry etching process to be performed on the wafer W may be, forexample, any one of reactive ion etching (RIE), deep RIE (DRIE), ionbeam etching (IBE), and Ar milling. As another example, the dry etchingprocess to be performed on the wafer W may be atomic layer etching(ALE). Also, the wet etching process to be performed on the wafer W maybe an etching process using, as etchant gas, at least one of Cl₂, HCl,CHF₃, CH₂F₂, CH₃F, H₂, BCL₃, SiCl₄, Br₂, HBr, NF₃, CF₄, C₂F₆, C₄F₈, SF₆,O₂, SO₂, and COS.

In some embodiments, a planarization process, such as a chemicalmechanical polish (CMP) process, an ion injection process, aphotolithography process, etc. may also be performed on the wafer W.

The wafer W may include, for example, silicon (Si). The wafer W mayinclude a semiconductor element, such as germanium (Ge), or a compoundsemiconductor, such as silicon carbide (SiC), gallium arsenide (GaAs),indium arsenide (InAs), and indium phosphide (InP). In some embodiments,the wafer W may have a silicon on insulator (SOI) structure. The wafer Wmay include a buried oxide layer. In some embodiments, the wafer W mayinclude a conductive area, for example, wells doped with impurities. Insome embodiments, the wafer W may have various device isolationstructures, such as shallow trench isolation (STI), which isolate theabove doped wells from each other. The wafer W may have a first surface,which is an active surface, and a second surface, which is opposite tothe first surface and is a non-active surface. The wafer W may bearranged on the heating plate 110 such that the second surface of thewafer W faces the heating plate 110.

Referring to FIG. 1A, it is illustrated that the wafer W is convex in adownward direction, that is, in a direction facing the heating plate110. However, embodiments are not limited thereto. The wafer W may havean upwardly convex shape or may have a saddle shape.

A plurality of support pins 115 may be arranged on a top surface of theheating plate 110. The plurality of support pins 115 may support thewafer W arranged on the heating plate 110. The plurality of support pins115 may prevent the wafer W from directly contacting the heating plate110, thereby preventing the wafer W from being contaminated by theheating plate 110.

In some embodiments, a heating device 117 having a patterned thin-plateshape may be arranged under the heating plate 110. However, embodimentsare not limited thereto and the heating device 117 may be provided inthe heating plate 110 or above the heating plate 110. The heating device117 may be, for example, an electrothermal device and may have variouspredetermined shapes to provide uniform heat to the wafer W loaded onthe heating plate 110.

In some embodiments, the heating device 117 may be divided into aplurality of areas so as to correspond to a plurality of regions of theheating plate 110. An example division structure of the heating device117 is indicated by broken lines in FIGS. 2A, 2B and 2C. Accordingly,the heating device 117 may provide different heat outputs onto differentportions of the heating plate 110. Even when a region of the heatingplate 110 has a higher or a lower temperature than other regions of theheating plate 110, the heating device 117 may control the heat outputsuch that the entire surface of the heating plate 110 has uniformtemperature distribution.

A plurality of vacuum ports 111, to which vacuum pressure is providedfrom the outside, may be formed on the heating plate 110. The pluralityof vacuum ports 111 may penetrate the heating plate 110 and may functionas a path through which vacuum pressure is provided. FIG. 1A indicatesthe vacuum pressure by using dashed arrows. In some embodiments, thevacuum ports 111 may be arranged on the heating plate 110 in variousshapes. Example shapes of the vacuum ports 111 will be described belowwith reference to FIGS. 2A, 2B and 2C. The vacuum ports 111 may pull thewafer W via the vacuum pressure such that the wafer W is fixed on theplurality of support pins 115.

Temperature sensors 113 may be provided in the heating plate 110.However, embodiments are not limited thereto, and the temperaturesensors 113 may be arranged on the top surface or the bottom surface ofthe heating plate 110. The temperature sensors 113 may detect thetemperature of the heating plate 110. The temperature sensors 113 may bearranged on a central region CR (see FIG. 2A), an edge region ER (seeFIG. 2A), and a middle region MR (see FIG. 2A) between the centralregion CR and the edge region ER, in a particular arrangement

First and second temperature controllers 121 and 123 may generate firstand second temperature control signals TCS1 and TCS2 for controllingpower outputs of first and second power supplies 131 and 133 byreceiving first and second temperature control commands TCC1 and TCC2according to a process recipe. Here, the first temperature controlsignal TCS1 may be a signal for controlling an output of a portion ofthe heating device 117, the portion corresponding to the central regionCR (see FIG. 2A) and the second temperature control signal TCS2 may be asignal for controlling an output of a portion of the heating device 117,the portion corresponding to the edge region ER (see FIG. 2A).

The first and second temperature controllers 121 and 123 may receivefirst and second temperatures T1 and T2, which are temperaturemeasurement values, from the temperature sensors 113. The firsttemperature T1 may be a temperature measured by the temperature sensors113 arranged at the central region CR (see FIG. 2A) of the heating plate110 and the second temperature T2 may be a temperature measured by thetemperature sensors 113 corresponding to the edge region ER (see FIG.2A) of the heating plate 110.

The first and second temperature controllers 121 and 123 may generatefirst and second feedback temperature control signals FTCS1 and FTCS2based on the first and second temperatures T1 and T2. The first feedbacktemperature control signal FTCS1 may be a signal corresponding to thecentral region CR (see FIG. 2A) of the heating plate 110 and the secondfeedback temperature control signal FTCS2 may be a signal correspondingto the edge region ER (see FIG. 2A) of the heating plate 110.

The first and second feedback temperature control signals FTCS1 andFTCS2 may be feedback signals based on the first and second temperaturesT1 and T2. For example, when the first temperature T1 is lower than atemperature according to a process recipe, the first temperaturecontroller 121 may generate the first feedback temperature controlsignal FTCS1 to increase the power output of the first power supply 131.On the contrary, when the second temperature T2 is higher than thetemperature according to the process recipe, the second temperaturecontroller 123 may generate the second feedback temperature controlsignal FTCS2 to decrease the power output of the second power supply133.

The first and second power supplies 131 and 133 may generate poweroutputs according to the first and second temperature control signalsTCS1 and TCS2 or the first and second feedback temperature controlsignals FTCS1 and FTCS2 and may provide the power outputs to the heatingdevice 117. The first power supply 131 may transmit the power output tothe heating device 117 corresponding to the central region CR (see FIG.2A) of the heating plate 110. The second power supply 133 may transmitthe power output to the heating device 117 corresponding to the edgeregion ER (see FIG. 2A) of the heating plate 110.

The wafer chucking controller 140 may control the electronic pressureregulator 150. The wafer chucking controller 140 may generate a pressurecontrol signal PCS for controlling the electronic pressure regulator 150based on an external wafer chucking command WCC.

The wafer chucking controller 140 may generate a feedback pressurecontrol signal FPCS, which is a signal for controlling the electronicpressure regulator 150, based on the first and second feedbacktemperature control signals FCS1 and FCS2. The wafer chucking controller140 may perform a certain calculation based on the first and secondfeedback temperature control signals FTCS1 and FTCS2 of the first andsecond temperature controllers 121 and 123. The wafer chuckingcontroller 140 may determine a degree of warpage of the wafer W via theabove calculation. According to one or more embodiments, the waferchucking controller 140 may generate the feedback pressure controlsignal FPCS based on the determined warpage of the wafer W. According toother embodiments, the wafer chucking controller 140 may generate thefeedback pressure control signal FPCS based on a result of the abovecalculation without determining warpage of the wafer W. The calculationof the wafer chucking controller 140 will be described again below.

In some embodiments, the electronic pressure regulator 150 may regulatean intensity of the vacuum pressure of the vacuum ports 111, based onthe pressure control signal PCS or the feedback pressure control signalFPCS. In some embodiments, the electronic pressure regulator 150 mayinclude a servo valve or a solenoid valve. According to otherembodiments, the electronic pressure regulator 150 may include anelectronic vacuum pressure transducer. The electronic pressure regulator150 may further include an internal pressure sensor for monitoring apressure output.

When wafer processing apparatuses according to the related art fix thewafer W by using the vacuum pressure method, the wafer processingapparatuses may fix the wafer W by applying maximum pressure, regardlessof the degree of warpage of the wafer W, by using a vacuum valvecontrolled in an on and off method. The fixing of the wafer W by usingthe vacuum pressure method generates turbulent air and causesnon-uniform heat loss of an edge of the wafer W, thereby deterioratinguniform thermal distribution on the entire surface of the wafer W.

According to one or more embodiments, whether or not the wafer W haswarpage and a degree of the warpage may be determined based on the firstand second feedback temperature control signals FTCS1 and FTCS2, and thewafer pressure control signal FPCS may be generated based on thedetermined degree of the warpage of the wafer W, and thus, the wafer Wmay be fixed by using optimum vacuum pressure. Here, the optimum vacuumpressure may be any one of minimum pressure for fixing the wafer W andminimum pressure for reducing warpage of the wafer W and uniformlyprocessing the wafer W. Accordingly, an excessive vacuum pressure thatis beyond necessity may not be applied to the wafer W and turbulent airbetween the wafer W and the heating plate 110 may be minimized.Accordingly, the reliability with respect to uniform processing of thewafer W may be improved.

The first and second temperature controllers 121 and 123 and the waferchucking controller 140 may include hardware, firmware, software, orcombinations thereof.

For example, the first and second temperature controllers 121 and 123and the wafer chucking controller 140 may include computing devices,such as a workstation computer, a desktop computer, a laptop computer, atablet computer, etc. The first and second temperature controllers 121and 123 and the wafer chucking controller 140 may include a simplecontroller, such as a hardware controller, a microprocessor, a complexprocessor, such as a central processing unit (CPU), a graphicsprocessing unit (GPU), etc., a processor including software,exclusive-use hardware, or firmware. The first and second temperaturecontrollers 121 and 123 and the wafer chucking controller 140 mayinclude a general-purpose computer, or application specific hardware,such as a digital signal processor (DSP), a field programmable gatearray (FPGA), an application specific integrated circuit (ASIC), etc.

In some embodiments, operations of the first and second temperaturecontrollers 121 and 123 and the wafer chucking controller 140 may berealized by using commands which may be read and executed by one or moreprocessors, and stored on a computer-readable recording medium. Here,the computer-readable recording medium may include certain mechanismsfor storing and/or transmitting information in a machine (for example, acomputing device)-readable form. For example, the computer-readablerecording medium may include read only memory (ROM), random-accessmemory (RAM), magnetic disk storage media, optical storage media, flashmemory devices, electrical, optical, acoustic, or other radio wavesignals (for example, a carrier wave, an infrared signal, a digitalsignal, etc.), and other random signals.

Firmware, software, routines, or instructions may be configured toperform the operations described with respect to the first and secondtemperature controllers 121 and 123 and the wafer chucking controller140 or other processes to be described hereinafter. For example, thefirst and second temperature controllers 121 and 123 and the waferchucking controller 140 may be realized by using software for generatinga signal, receiving data for feedback, performing certain calculationsand regulating processes, with respect to processing the wafer W.

However, this is for convenience of explanation. The operations of thefirst and second temperature controllers 121 and 123 and the waferchucking controller 140 may be performed by using computing devices,processors, controllers, or other devices executing firmware, software,routine, instructions, etc.

FIG. 1B is a diagram for describing a wafer processing apparatus 100 baccording to other embodiments.

For convenience of description, aspects that are the same as the aspectsdescribed with reference to FIG. 1A will not be repeated.

Referring to FIG. 1B, the wafer processing apparatus 100 b may furtherinclude a first measuring device 132 (i.e., a meter) and a secondmeasuring device 134, in addition to the components of the waferprocessing apparatus 100 a illustrated in FIG. 1A.

The first measuring device 132 may be arranged between the first powersupply 131 and the heating plate 110. The first measuring device 132 maybe connected to a path through which a power output of the first powersupply 131 is provided to the heating plate 110. The second measuringdevice 134 may be arranged between the second power supply 133 and theheating plate 110. The second measuring device 134 may be connected to apath through which a power output of the second power supply 133 isprovided to the heating plate 110.

The first and second measuring devices 132 and 134 may be any one of avoltmeter, an ammeter, and a wattmeter. In some embodiments, the firstmeasuring device 132 may measure a first power output O1, which is thepower output of the first power supply 131. The first power output O1may be a power output delivered to the heating device 117 correspondingto the central region CR (see FIG. 2A) of the heating plate 110, and maybe any one of voltage, current, or electricity. In some embodiments, thesecond measuring device 134 may measure a second power output O2, whichis the power output of the second power supply 133. The second poweroutput O2 may be a power output delivered to the heating device 117corresponding to the edge region ER (see FIG. 2A) of the heating plate110, and may be any one of voltage, current, and electricity.

The wafer chucking controller 140 may generate a feedback pressurecontrol signal FPCS based on the first and second power outputs O1 andO2. In more detail, the wafer chucking controller 140 may perform acertain calculation based on the first and second power outputs O1 andO2 and then, based on a result of the calculation, may generate thefeedback pressure control signal FPCS for controlling the electronicpressure regulator 150.

FIG. 1C is as diagram for describing a wafer processing apparatus 100 caccording to other embodiments.

For convenience of description, aspects that are the same as the aspectsdescribed with reference to FIG. 1A will not be repeated.

Referring to FIG. 1C, unlike the wafer processing apparatus 100 aillustrated in FIG. 1A, the wafer processing apparatus 100 c may includea process controller 120 configured to control a temperature of theheating plate 110 and control an output pressure of the electronicpressure regulator 150. In some embodiments, the process controller 120may perform the functions of the first and second temperaturecontrollers 121 and 123 and the wafer chucking controller 140 of FIG.1A.

The process controller 120 may include various types of computingdevices or processor devices, as described above in FIG. 1A with respectto the first and second temperature controllers 121 and 123 and thewafer chucking controller 140. The process controller 120 may includesoftware and/or firmware for controlling the temperature of the heatingplate 110 and controlling the pressure output of the electronic pressureregulator 150.

In some embodiments, the process controller 120 may generate first andsecond temperature control signals TCS1 and TCS2 and a pressure controlsignal PCS by receiving a wafer process command WPC according to aprocess recipe.

In some embodiments, the process controller 120 may receive signals withrespect to first and second temperatures T1 and T2 from the temperaturesensors 113, generate first and second feedback temperature controlsignals FTCS1 and FTCS2 for controlling the temperature of the heatingplate 110 by using the signals with respect to the first and secondtemperatures T1 and T2, and transmit the first and second feedbacktemperature control signals FTCS1 and FTCS2 to the first and secondpower supplies 131 and 133, respectively.

In some embodiments, the process controller 120 may generate a feedbackpressure control signal FPCS for controlling the electronic pressureregulator 150, based on the first and second feedback temperaturecontrol signals FTCS1 and FTCS2.

FIGS. 2A, 2B and 2C are plan views for describing the heating plate 110according to embodiments.

Referring to FIGS. 2A, 2B and 2C, a central region CR, an edge regionER, and a middle region MR between the central region CR and the edgeregion ER may be defined on the heating plate 110.

In some embodiments, as illustrated in FIGS. 2A, 2B and 2C, the vacuumports 111 may be arranged in circular symmetry with respect to thecenter of the heating plate 110. Based on this arrangement of the vacuumports 111, the wafer W (see FIG. 1A) loaded on the heating plate 110 maybe fixed via uniform pressure.

In the example of FIG. 2A, the vacuum ports 111 may be arranged at themiddle region MR of the heating plate 110. In the example of FIG. 2B,the vacuum ports 111 may be arranged at the central region CR of theheating plate 110. In the example of FIG. 2C, the vacuum ports 111 maybe arranged at the edge region ER of the heating plate 110.

FIG. 3 is a flowchart of a wafer processing method according toembodiments.

Referring to FIGS. 1A and 3, the heating plate 110 may be heated inoperation P110.

As described above, the first and second temperature controllers 121 and123 may generate the first and second temperature control signals TCS1and TCS2, respectively, based on the first and second temperaturecontrol commands TCC1 and TCC2, respectively, according to the processrecipe.

The first and second power supplies 131 and 133 may heat the heatingplate 110 to have a uniform temperature on the entire surface of theheating plate 110, based on the received first and second temperaturecontrol signals TSC1 and TSC2.

FIG. 4 is a graph showing a result of an experimental example fordescribing a wafer processing method according to embodiments. In moredetail, FIG. 4 indicates a temperature of the edge region ER (see FIG.2A) of the heating plate 110 and a power output of the second powersupply 133 with respect to the processing of the wafer W, according totime.

In the graph of FIG. 4, the vertical axis indicates the temperature ofthe heating plate 110 or the power output of the second power supply 133and the horizontal axis indicates time. Also, in the graph of FIG. 4,the solid line indicates the temperature of the edge region ER (see FIG.2A) of the heating plate 110, and broken lines indicate the second powersupply 133 output.

Referring to FIGS. 1A, 2A, 3, and 4, in operation P120, the wafer W maybe loaded on the heating plate 110. The loading of the wafer W may beperformed by a transporting robot, and the loaded wafer may be fixed viavacuum pressure of the vacuum ports 111.

In the experimental example of FIG. 4, a wafer that is substantiallyflat (that is, without warpage) is loaded at a first time point t1 and awafer having warpage is loaded at a second time point t2.

When the wafer W loaded at the second time point t2 is loaded such thata non-active surface thereof faces the heating plate 110, a distancebetween the edge region ER of the heating plate 110 and the wafer W isgreater than a distance between the central region CR of the heatingplate 110 and the wafer W. The wafer W of the experimental example mayhave warpage of about 350 μm. Here, the warpage of about 350 μmindicates that a height difference between a highest point and a lowestpoint with respect to a top surface of the wafer W is about 350 μm.

Generally, the temperature of the wafer W directly before the wafer W isloaded on the heating plate 110 is lower than the temperature of theheating plate 110 according to a process recipe, and thus, thetemperature of the edge region ER of the heating plate 110 may decreasedirectly after the wafer W is loaded.

Compared with the first time point t1 at which the flat wafer is loaded,the second time point t2 shows a relatively less temperature drop of theedge region ER of the heating plate 110 directly after the wafer W isloaded. Accordingly, the power output of the second power supply 133 atthe second time point t2 is less than the power output of the firstpower supply 131 at the first time point t1.

Table 1 below shows temperatures of the heating device 117 correspondingto the central region CR, the middle region MR, and the edge region ERof the heating plate 110 right after the flat wafer is loaded, thetemperatures of the central region CR, the middle region MR, and theedge region ER of the heating plate 110 right after the wafer havingwarpage is loaded, and also a ratio of the corresponding temperatures.

TABLE 1 Flat wafer Wafer having Ratio (A) warpage (B) (B/A) Lowestaverage temperature 108.9° C. 109.5° C. 100.6% Lowest temperature of108.2° C. 108.9° C. 100.6% central region Lowest temperature of 108.3°C. 109.3° C. 100.9% middle region Lowest temperature of 108.2° C. 109.7°C. 100.5% edge region

As described above, the plurality of temperature sensors are arranged atpredetermined locations on the entire surface of the heating plate 110and Table 1 shows minimum values of the measurement values of thetemperature sensors arranged in the central region CR, the middle regionMR, and the edge region ER.

The ratio between the changed temperatures right after the flat wafer Wand the wafer W having warpage are loaded is about 100.5% to about100.9%, which indicates a rather low identifying characteristic.

Next, referring to FIGS. 1A and 3, in operation P130, the heating device117 may be controlled such that the heating plate 110 has a pre-settemperature.

Operation P130 may be performed substantially simultaneously with theloading of the wafer W in operation P120, or right after the loading ofthe wafer W in operation P120.

As described above, the controlling of the heating device 117 mayinclude: measuring the temperature of the heating plate 110 for eachregion, the temperature including the first and second temperatures T1and T2; generating the first and second feedback temperature controlsignals FTCS1 and FTCS2 based on the temperature for each region; andproviding power outputs to portions of the heating device 117, theportions corresponding to the different regions of the heating plate110, based on the first and second feedback temperature control signalsFTCS1 and FTCS2.

Next, referring to FIGS. 1A and 3, vacuum pressure for chucking thewafer W may be regulated based on the power outputs of the heatingdevice 117, in operation P140.

Table 2 below shows the power outputs of the heating device 117corresponding to the central region CR, the middle region MR, and theedge region ER of the heating plate 110, right after the first timepoint t1 and the second time point t2 at which the flat wafer W and thewafer W having warpage are loaded respectively.

TABLE 2 Flat wafer Wafer having Ratio (A) warpage (B) (B/A) Highestpower output of 84.9 W 94.9 W 111.8% central region Highest power outputof 109.9 W  49.6 W 45.1% middle region Highest power output of 55.1 W25.7 W 46.6% edge region Difference in power outputs 29.8 W 69.2 W232.2% between central region and edge region

Compared to Table 1 in which temperature differences between the wafer Whaving no warpage and the wafer W having warpage for the central regionCR, the middle region MR, and the edge region ER of the heating plate110, right after the wafers W are loaded, are less, it is identified inTable 2 that a difference between power outputs of the heating device117 corresponding to the central region CR and the edge region ER islarge, for the wafer B having warpage and the wafer A that is flat.

For convenience of description, the difference between the power outputof the heating device 117 (or the power supply) corresponding to thecentral region CR and the power output of the heating device 117 (or thepower supply) corresponding to the edge region ER will be referred to asa center-edge power output difference.

In some embodiments, the wafer chucking controller 140 may calculate thecenter-edge power output difference. Furthermore, in some embodiments,the wafer chucking controller 140 may calculate a ratio between thecenter-edge power output difference of the wafer B having warpage andthe center-edge power output difference of the wafer A having nowarpage. As shown in Table 2, the ratio between the center-edge poweroutput difference of the wafer B having warpage of about 350 μm and thecenter-edge power output difference of the wafer A that is flat may beabout 232.2%, which indicates a high identifying characteristic withrespect to whether or not warpage occurs and the degree of the warpage.

In FIG. 2, a maximum power output of the power outputs of the heatingdevice 117 corresponding to the central region CR is compared with amaximum power output of the power outputs of the heating device 117corresponding to the edge region ER. However, embodiments are notlimited thereto. In other embodiments, the wafer chucking controller 140may calculate the center-edge power output difference by comparing aminimum power output of the power outputs of the heating device 117corresponding to the central region CR to a minimum power output of thepower outputs of the heating device 117 corresponding to the edge regionER.

Also, as will be described below, the wafer chucking controller 140 maydetermine whether or not warpage occurs to the wafer and the degree ofwarpage. In some embodiments, when the wafer chucking controller 140determines that the wafer W has warpage having a downwardly convexshape, the wafer chucking controller 140 may calculate the center-edgepower output difference by comparing a maximum power output of the poweroutputs of the heating device 117 corresponding to the central region CRwith a minimum power output of the power outputs of the heating device117 corresponding to the edge region ER.

In other embodiments, when the wafer chucking controller 140 determinesthat the wafer W has warpage having an upwardly convex shape, the waferchucking controller 140 may calculate the center-edge power outputdifference by comparing a minimum power output of the power outputs ofthe heating device 117 corresponding to the central region CR with amaximum power output of the power outputs of the heating device 117corresponding to the edge region ER.

In other embodiments, the wafer chucking controller 140 may calculatethe center-edge power output difference by comparing an average poweroutput of the power outputs of the heating device 117 corresponding tothe central region CR with an average power output of the power outputsof the heating device 117 corresponding to the edge region ER. In otherembodiments, the wafer chucking controller 140 may calculate thecenter-edge power output difference by comparing a median power outputof the power outputs of the heating device 117 corresponding to thecentral region CR with a median power output of the power outputs of theheating device 117 corresponding to the edge region ER.

According to example embodiments, the wafer chucking controller 140 maydetermine whether or not warpage occurs to the wafer W based on thefirst and second feedback temperature control signals without anassistance of an additional height measuring sensor. In someembodiments, the wafer chucking controller 140 may determine whether ornot warpage occurs to the wafer W and the degree of warpage by using alook-up function about data about a center-edge power output differenceof a wafer W currently in process, or by comparison, etc., betweenprevious online/offline data. In other embodiments, the wafer chuckingcontroller 140 may determine whether or not warpage occurs to the waferW and the degree of warpage by using a look-up function about data abouta ratio between a center-edge power output difference of the flat waferW and a center-edge power output difference of the wafer W currently inprocess, or by comparison, etc., between previous online/offline data.

The wafer chucking controller 140 may generate the feedback pressurecontrol signal FPCS based on the warpage of the wafer W. For example,according to the feedback pressure control signal FPCS, when the wafer Whas a large warpage, the electronic pressure regulator 150 may beconfigured to output a greater vacuum pressure, and when the wafer W hassmall warpage, the electronic pressure regulator 150 may be configuredto output a less vacuum pressure.

In other embodiments, the wafer chucking controller 140 may generate thefeedback pressure control signal FPCS based on the first and secondfeedback temperature control signals FTCS1 and FTCS2. In more detail,the wafer chucking controller 140 may generate the feedback pressurecontrol signal FPCS by using a look-up function about data about anoptimum pressure control signal based on a center-edge power outputdifference of the wafer W currently in process, or by comparison, etc.,between previous online/offline data.

Above, the wafer processing method performed by the wafer processingapparatus 100 a of FIG. 1A is described. However, it will be understoodby one of ordinary skill in the art that the wafer processingapparatuses 100 b and 100 c of FIGS. 1B and 1C may process the wafer byusing substantially the same method.

FIG. 5 is a diagram for describing a wafer processing apparatus 200according to other embodiments.

FIG. 6 is a schematic top view of a heating plate 210 included in thewafer processing apparatus 200, according to example embodiments.

For convenience of description, aspects that are the same as the aspectsdescribed with reference to FIG. 1A will not be repeated.

Referring to FIGS. 5 and 6, the wafer processing apparatus 200 mayinclude the heating plate 210, first through third temperaturecontrollers 121, 123, and 125, first through third power supplies 131,133, and 135, the wafer chucking controller 140, and first and secondelectronic pressure regulators 151 and 153.

Temperature sensors 213, support pins 215, and a heating device 217 maybe substantially the same as the temperature sensors 113, the supportpins 115, and the heating device 117 described above with reference toFIG. 1A, respectively.

Inner vacuum ports 2111 and outer vacuum ports 2110 may be formed on theheating plate 210. Each of the inner vacuum ports 2111 and the outervacuum ports 2110 may be arranged in circular symmetry with respect tothe center of the top surface of the heating plate 210. FIG. 6illustrates that the inner vacuum ports 2111 are formed at a middleregion MR and the outer vacuum ports 2110 are formed at an edge regionER. However, embodiments are not limited thereto.

The first through third temperature controllers 121, 123, and 125 maygenerate first through third temperature control signals TCS1, TCS2, andTCS3 respectively, based on first through third temperature controlcommands TCC1, TCC2, and TCC3, according to a process recipe. The firsttemperature control signal TCS1 may be a signal for controlling a poweroutput of the first power supply 131 corresponding to a central regionCR of the heating plate 210. The second temperature control signal TCS2may be a signal for controlling a power output of the second powersupply 133 corresponding to the edge region ER of the heating plate 210.The third temperature control signal TCS3 may be a signal forcontrolling a power output of the third power supply 135 correspondingto the middle region MR of the heating plate 210.

The first through third power supplies 131, 133, and 135 mayrespectively provide operational power to portions of the heating device217, the portions corresponding to the central region CR, the edgeregion ER, and the middle region MR of the heating plate 210, inresponse to the first through third temperature control signals TCS1,TCS2, and TCS3.

The plurality of temperature sensors 213 may measure first through thirdtemperatures T1, T2, and T3, which are temperatures of the centralregion CR, the edge region ER, and the middle region MR of the heatingplate 210, respectively.

The first through third temperature controllers 121, 123, and 125 mayread signals about the first through third temperatures T1, T2, and T3,respectively, and generate first through third feedback temperaturecontrol signals FTCS1, FTCS2, and FTCS3, based on the read signals.Because the first through third power supplies 131, 133, and 135 supplypower outputs to the heating device 217, according to the first throughthird feedback temperature control signals FTCS1, FTCS2, and FTCS3,uniform temperature distribution may be realized on the entire surfaceof the heating plate 210. Thus, uniform processing of the wafer W isfeasible.

The wafer chucking controller 140 may generate first and second pressurecontrol signals PCS1 and PCS2 based on a wafer chucking command WCC. Thefirst electronic pressure regulator 151 may regulate vacuum pressure ofthe inner vacuum ports 2111 based on the first pressure control signalPCS1. The second electronic pressure regulator 153 may regulate vacuumpressure of the outer vacuum ports 2110 based on the second pressurecontrol signal PCS2. Depending on cases, the pressure of the outervacuum ports 2110 and the pressure of the inner vacuum ports 2111 may bedifferent from each other.

The wafer chucking controller 140 may generate first and second feedbackpressure control signals FPCS1 and FPCS2 based on the first throughthird feedback temperature control signals FTCS1, FTCS2, and FTCS3. Thewafer chucking controller 140 may determine whether or not warpageoccurs to the wafer W based on the first through third feedbacktemperature control signals FTCS1, FTCS2, and FTCS3. The wafer chuckingcontroller 140 may determine a vertical distance from a certain locationon the wafer W to the heating plate 210 based on the first through thirdfeedback temperature control signals FTCS1, FTCS2, and FTCS3. In someembodiments, the wafer chucking controller 140 may determine athree-dimensional shape of the wafer W and generate the first and secondfeedback pressure signals FPCS1 and FPCS2 for chucking the wafer W viaoptimum vacuum pressure, based on the three-dimensional shape of thewafer W. The first and second electronic pressure regulators 151 and 153may regulate the pressure of the inner vacuum ports 2111 and thepressure of the outer vacuum ports 2110, respectively, based on thefirst and the second feedback pressure signals FPCS1 and FPCS2,respectively.

FIGS. 5 and 6 illustrate that two electronic pressure regulators areprovided to regulate the pressure of the inner vacuum ports 2111 andpressure of the outer vacuum ports 2110, respectively. However,embodiments are not limited thereto. For example, each vacuum port maybe connected to a different electronic pressure regulator and adifferent pressure may be applied to each vacuum port. Furthermore,additional vacuum ports may be provided at the central region CR, inaddition to the edge region ER and the middle region MR.

FIG. 7 is a flowchart of a wafer processing method according toembodiments.

For convenience of description, aspects that are the same as the aspectsdescribed with reference to FIG. 3 will not be repeated.

Operations P210 and P220 of FIG. 7 are substantially the same asoperations P110 and P120 of FIG. 3, respectively.

Referring to FIGS. 5 through 7, in operation P230, the heating device217 may be controlled such that the heating plate 210 has a pre-settemperature.

Operation P230 may be performed substantially simultaneously with theloading of the wafer W in operation P220, or right after the loading ofthe wafer W in operation P220.

The controlling of the heating device 218 may be similar to what isdescribed above. In more detail, the controlling of the heating device217 may include: measuring the temperature of the heating plate 210 foreach region, the temperature including the first through thirdtemperatures T1 through T3; generating the first through third feedbacktemperature control signals FTCS1 through FTCS3 based on the temperaturefor each region; and providing power outputs to the portions of theheating device 217, the portions corresponding to the different regionsof the heating plate 210, based on the first through third feedbacktemperature control signals FTCS1 through FTCS3.

Next, referring to FIGS. 1A and 3, vacuum pressure for chucking thewafer W may be regulated based on the power outputs of the heatingdevice 217, in operation P240.

In some embodiments, the wafer chucking controller 140 may compare thepower outputs of the heating device 217 corresponding to the centralregion CR, the edge region ER, and the middle region MR of the heatingplate 210, respectively, with reference values. The reference values maybe power outputs of the heating device 217 corresponding to the centralregion CR, the edge region ER, and the middle region MR of the heatingplate 210, respectively, right after the wafer W having no warpage isloaded onto the heating plate 210.

In some embodiments, the wafer chucking controller 140 may calculatedistances from certain locations on the wafer W to the heating plate210, based on differences between the power outputs of the heatingdevice 217 corresponding to the central region CR, the edge region ER,and the middle region MR of the heating plate 210, respectively, and thereference values. In some embodiments, the wafer chucking controller 140may determine a three-dimensional shape of the wafer W based on thecalculated distances.

In other embodiments, the wafer chucking controller 140 may determinethe three-dimensional shape of the wafer W by using a look-up functionabout data about the differences between the reference values and thepower outputs of the heating device 217 corresponding to the centralregion CR, the edge region ER, and the middle region MR of the heatingplate 210, respectively, or by comparison, etc., between previousonline/offline data.

The wafer chucking controller 140 may generate the first and secondfeedback pressure control signals FPCS1 and FPCS2 based on thethree-dimensional shape of the wafer W. The first and second electronicpressure regulators 151 and 153 may output vacuum pressure forminimizing warpage of the wafer W, based on the first and secondfeedback pressure control signals FPCS1 and FPCS2.

According to example embodiments, even when the wafer W to be processedhas warpage of an irregular shape, the first and second electronicpressure regulators 151 and 153 may perform the controlling operation ofminimizing the warpage. Thus, the reliability with respect to uniformprocessing of the wafer W may be increased.

FIGS. 8A and 8B are plan views of a top surface of the heating plate 110for describing chucking of the wafer W, according to embodiments.

The inner vacuum ports 2111 and the outer vacuum ports 2110 indicated byusing relatively thick lines from among the inner vacuum ports 2111 andthe outer vacuum ports 2110 in FIGS. 8A and 8B indicate that thecontrolling operations are performed thereon based on the feedbackpressure control signals FPCS1 and FPCS2. Also, the inner vacuum ports2111 and the outer vacuum ports 2110 indicated by using relatively thinlines from among the inner vacuum ports 2111 and the outer vacuum ports2110 indicate that the controlling operations are performed thereonbased on the feedback pressure control signals FPCS1 and FPCS2.

The controlling operation of the first and second electronic pressureregulators 151 and 153 based on the first and second feedback pressurecontrol signals FPCS1 and FPCS2 may be sequentially performed. Forexample, as illustrated in FIG. 8A, after the inner vacuum ports 2111are controlled based on the first feedback pressure control signalsFPCS1 to receive optimum vacuum pressure, as illustrated in FIG. 8B, theouter vacuum ports 2110 may be controlled based on the second feedbackpressure control signals FPCS2 to receive optimum vacuum pressure.

However, embodiments are not limited thereto. The optimizationoperations based on the first and second feedback pressure controlsignals FPCS1 and FPCS2 may be substantially simultaneously performed onthe inner vacuum ports 2111 and the outer vacuum ports 2110, or may befirst performed on the outer vacuum ports 2110 and then on the innervacuum ports 2111.

FIG. 9 is a diagram for describing a wafer processing apparatus 300according to embodiments.

For convenience of description, aspects that are the same as the aspectsdescribed with reference to FIG. 1A will not be repeated.

Referring to FIG. 9, the wafer processing apparatus 300 may include theheating plate 110, the vacuum ports 111, the support pins 115, theheating device 117, a temperature controller 320, the first and secondpower supplies 131 and 133, and a pressure valve 350.

The heating plate 110, the vacuum ports 111, the support pins 115, theheating device 117, and the first and second power supplies 131 and 133are substantially the same as the components described with reference toFIG. 1A.

The pressure valve 350 may be connected to an external device, such as avacuum pump, and vacuum pressure generated by the vacuum pump may beprovided to the vacuum ports 111 through the pressure valve 350. Thepressure valve 350 may supply substantially constant pressure to thevacuum ports 111, unlike the electronic pressure regulator 160 in FIG.1A.

The temperature controller 320 may generate first and second temperaturecontrol signals TCS1 and TCS2 for controlling the first and second powersupplies 131 and 133, respectively, based on a wafer processing commandWPC according to process recipe.

The temperature controller 320 may determine whether or not the wafer Whas warpage and the degree of the warpage, by using the same method asthe method described with reference to FIGS. 1A, 1B, 1C, 2A, 2B, 2C, 3and 4. In more detail, a wafer warpage controller 340 may generate afirst warpage-based temperature control signal WBTCS1 and a secondwarpage-based temperature control signal WBTCS2, based on the degree ofthe warpage of the wafer W.

According to the related art, when a temperature drop of the heatingplate 110 due to the loading of the wafer W is less, the temperaturecontroller 320 may generate signals for controlling the first and secondpower supplies 131 and 133 to output relatively low power outputs.

According to embodiments, the temperature controller 320 may determinethe warpage of the wafer W based on the first and second temperatures T1and T2 of the heating plate 110. The temperature controller 320 maygenerate the first and second warpage-based temperature control signalsWBTCS1 and WBTCS2 for substantially uniformly heating the entire surfaceof the wafer W.

In more detail, when a drop of the first temperature T1, which is thetemperature of the central region CR (see FIG. 2A) of the heating plate110, is greater than a drop of the second temperature T2, which is thetemperature of the edge region ER (see FIG. 2A) of the heating plate110, the temperature controller 320 may determine that the wafer W haswarpage of a downwardly convex shape.

Accordingly, the wafer W may generate the first and second warpage-basedtemperature control signals WBTCS1 and WBTCS2 for allowing the poweroutput transmitted to a portion of the heating device 117, the portioncorresponding to the edge region ER (see FIG. 2A) of the heating plate110, to be greater than the power output transmitted to a portion of theheating device 117, the portion corresponding to the central region CR(see FIG. 2A) of the heating plate 110. Accordingly, even when thewarpage occurs to the wafer W, the temperature of the entire surface ofthe wafer W may be uniformly controlled, and thus, uniform processing ofthe wafer W may be feasible.

FIG. 10 is a flowchart of a wafer processing method according toembodiments.

Operations P310 and P320 of FIG. 10 are substantially the same asoperations P110 and P120 of FIG. 3.

Referring to FIGS. 9 and 10, warpage of the wafer W may be determinedbased on measurement values of the temperature sensors 113, in operationP330.

The temperature controller 320 may determine the warpage of the wafer Wbased on data about a previous feedback temperature control signalaccording to the first and second temperatures T1 and T2 of the heatingplate 110.

Next, in operation P340, the heating device 117 may be controlled basedon the warpage of the wafer W.

The controlling of the heating device 117 may include generating, viathe temperature controller 320, the first and second warpage-basedtemperature control signals WBTCS1 and WBTCS2, and supplying, via thefirst and second power supplies 131 and 133, power outputs generatedbased on the first and second warpage-based temperature control signalsWBTCS1 and WBTCS2 to the heating device 117. As described above, theheating device 117 may be controlled to output relatively more heat fora portion of the heating plate 110, the portion relatively farther apartfrom the wafer W.

FIG. 11 is an exploded perspective view schematically showing maincomponents of a bake apparatus BA according to example embodiments.

Referring to FIG. 11, the bake apparatus BA may further include achamber 170, a transporting robot 180, and a base module 190, inaddition to the components included in the wafer processing apparatus100 a of FIG. 1A.

However, embodiments are not limited thereto. The bake apparatus BA mayfurther include the chamber 170, the transporting robot 180, and thebase module 190, in addition to the components included in the waferprocessing apparatuses 100 b, 100 c, 200, and 300 of FIGS. 1B, 1C, 5,and 9.

The transporting robot 180 may introduce a wafer into the bake apparatusBA or withdraw the wafer fully processed from the bake apparatus BA.

The chamber 170 may include an exhaust structure for exhausting gasgenerated during heating of the wafer. The chamber 170 may isolate thewafer from the outside while a processing operation is performed. Thechamber 170 may prevent the heat for processing the wafer from beingdischarged to the outside of the chamber 170 and prevent the wafer frombeing contaminated by particles outside the chamber 170. The chamber 170may cover both of the heating plate 110 and the wafer, or may cover onlythe wafer.

The base module 190 may support various components included in the bakeapparatus BA, such as the heating plate 110, the chamber 170, etc.

When the wafer is transported by the transporting robot 180, the chamber170 may be opened, the wafer may be loaded on the heating plate by thetransporting robot 180, and the chamber 170 may be closed. Next, whenthe wafer is sufficiently heated, the chamber 170 may be opened againand the wafer may be carried out by the transporting robot 180.

FIG. 12 is a block diagram of a system SYS including the bake apparatusBA, according to embodiments.

Referring to FIG. 12, the system SYS may include a spin coater SC, alithography apparatus LA, the bake apparatus BA, and a developing deviceDA.

Processes performed by the system SYS may include manufacturing asemiconductor wafer or a semiconductor structure including a waferincluding a circuit structure. The processes performed by the system SYSmay include, for example, a semiconductor process based on deepultra-violet (DUV) or extreme UV (EUV).

The spin coater SC may provide a photoresist layer on a semiconductorstructure SS by using a spin coating method.

The bake apparatus BA may be the bake apparatus BA described withreference to FIG. 12. In some embodiments, the bake apparatus BA mayperform a soft bake process after the photoresist layer is coated on thewafer by the spin coater SC. In some embodiments, the bake apparatus BAmay further perform a post exposure bake (POB) process after an exposureprocess by the lithography apparatus LA, and a hard bake process after adeveloping process by the developing device DA.

The lithography apparatus LA may perform an EUV lithography process. Thelithography apparatus LA may include a measuring station and an exposurestation.

The lithography apparatus LA may be a dual stage-type apparatusincluding two wafer tables. The wafer tables may respectively be anexposure station for exposure and a measuring station for measurement.Accordingly, while the semiconductor structure SS on one wafer table isexposed, the semiconductor structure SS on the other wafer table may bemeasured before being exposed. Because measuring alignment marksrequires much time and the lithography process is a bottleneck processof the overall semiconductor process, when two wafer tables areprovided, productivity of the semiconductor devices may be significantlyincreased. However, embodiments are not limited thereto. The lithographyapparatus LA may include a mono stage-type lithography apparatusincluding a single wafer table.

The developing apparatus DA may form photoresist patterns by developingan exposed photoresist layer.

The system SYS may further include an inspection apparatus forinspection after exposure, according to necessity. The inspectionapparatus may include a scatterometer, such as an angle-resolvedscatterometer or a spectroscopic scatterometer.

The system SYS may further include, for example, an etching apparatus.The etching apparatus may etch the wafer by using the developedphotoresist layer as an etch mask. According to other embodiments, thesystem SYS may further include apparatuses for performing an ion implantprocess, a deposition process, etc.

While embodiments been particularly shown and described with referenceto embodiments thereof, it will be understood that various changes inform and details may be made therein without departing from the spiritand scope of the following claims.

What is claimed is:
 1. A wafer processing apparatus comprising: aheating plate through which a plurality of vacuum ports is formed, and acentral region and an edge region surrounding the central region aredefined; a plurality of temperature sensors equipped in the heatingplate; a heater configured to heat the heating plate; a first powersupply and a second power supply configured to provide operational powerto different portions of the heater; a first temperature controllerconfigured to generate a first feedback temperature control signal forcontrolling power output of the first power supply based on a firstmeasurement value generated by the plurality of temperature sensors; asecond temperature controller configured to generate a second feedbacktemperature control signal for controlling power output of the secondpower supply based on a second measurement value generated by theplurality of temperature sensors; an electronic pressure regulatorconfigured to provide vacuum pressure for fixing a wafer disposed on theheating plate to the plurality of vacuum ports and regulate pressure ofthe plurality of vacuum ports; and a wafer chucking controllerconfigured to control the electronic pressure regulator, and generate afeedback pressure control signal for controlling the pressure of theelectronic pressure regulator based on the first feedback temperaturecontrol signal and the second feedback temperature control signal. 2.The wafer processing apparatus of claim 1, wherein the wafer chuckingcontroller is further configured to identify a power difference betweenthe first power supply and the second power supply based on the firstfeedback temperature control signal and the second feedback temperaturecontrol signal.
 3. The wafer processing apparatus of claim 1, whereinthe plurality of temperature sensors comprises first temperature sensorscorresponding to the central region and second temperature sensorscorresponding to the edge region, wherein the first temperature sensorsare configured to generate the first measurement value and the secondtemperature sensors are configured to generate the second measurementvalue, wherein the first temperature controller is further configured togenerate the first feedback temperature control signal based on thefirst measurement value, and wherein the second temperature controlleris further configured to generate the second feedback temperaturecontrol signal based on the second measurement value.
 4. The waferprocessing apparatus of claim 1, wherein the wafer chucking controlleris further configured to determine whether or not warpage of the waferoccurs based on the first feedback temperature control signal and thesecond feedback temperature control signal, directly after the wafer isloaded.
 5. The wafer processing apparatus of claim 1, wherein the waferchucking controller is further configured to identify a differencebetween a first power output of the first power supply and a secondpower output of the second power supply, directly after the wafer isloaded.
 6. The wafer processing apparatus of claim 5, wherein the waferchucking controller is further configured to identify a ratio of thedifference to a reference value, directly after the wafer is loaded. 7.The wafer processing apparatus of claim 6, wherein the reference valuecorresponds to a difference between the first power output of the firstpower supply and the second power output of the second power supply,directly after a flat wafer is loaded.
 8. The wafer processing apparatusof claim 1, wherein the wafer chucking controller is further configuredto identify a degree of warpage of the wafer based on the first feedbacktemperature control signal and the second feedback temperature controlsignal, directly after the wafer is loaded.
 9. The wafer processingapparatus of claim 8, wherein the wafer chucking controller is furtherconfigured to generate the feedback pressure control signal based on thedegree of warpage of the wafer.
 10. The wafer processing apparatus ofclaim 1, wherein the first power supply is configured to provide firstpower to a central portion of the heater corresponding to the centralregion, and wherein the second power supply is configured to providesecond power to an edge portion of the heater corresponding to the edgeregion.
 11. A wafer processing apparatus comprising: a heating platethrough which a plurality of vacuum ports is formed, and a centralregion, an edge region surrounding the central region, and a middleregion between the central region and the edge region are defined; aplurality of temperature sensors configured to measure a temperature ofthe heating plate; a heater configured to heat the heating plate; afirst power supply, a second power supply and a third power supplyconfigured to provide operational power to the heater; a firsttemperature controller configured to generate a first feedbacktemperature control signal for controlling a first power output of thefirst power supply based on a first measurement value of the pluralityof temperature sensors; a second temperature controller configured togenerate a second feedback temperature control signal for controlling asecond power output of the second power supply based on a secondmeasurement value of the plurality of temperature sensors; a thirdtemperature controller configured to generate a third feedbacktemperature control signal for controlling a third power output of thethird power supply based on a third measurement value of the pluralityof temperature sensors; an electronic pressure regulator configured toregulate pressure of the plurality of vacuum ports; and a wafer chuckingcontroller configured to control the electronic pressure regulator,wherein the plurality of vacuum ports comprises: a plurality of firstvacuum ports arranged in circular symmetry with respect to the center ofthe heating plate; and a plurality of second vacuum ports arranged incircular symmetry with respect to the center of the heating plate andfarther from the central region of the heating plate than the pluralityof first vacuum ports, wherein the electronic pressure regulatorcomprises: a first electronic pressure regulator configured to regulatepressure of the plurality of first vacuum ports; and a second electronicpressure regulator configured to regulate pressure of the plurality ofsecond vacuum ports, and wherein the wafer chucking controller isfurther configured to generate a first feedback pressure control signaland a second feedback pressure control signal configured to control,respectively, pressure of the first electronic pressure regulator andthe second electronic pressure regulator based on the first feedbacktemperature control signal, the second feedback temperature controlsignal and the third feedback temperature control signal.
 12. The waferprocessing apparatus of claim 11, wherein the plurality of temperaturesensors comprises first temperature sensors corresponding to the centralregion, second temperature sensors corresponding to the edge region, andthird temperature sensors corresponding to the middle region, whereinthe first temperature sensors are configured to generate the firstmeasurement value, the second temperature sensors are configured togenerate the second measurement value and the third temperature sensorsare configured to generate the third measurement value, wherein thefirst temperature controller is further configured to generate the firstfeedback temperature control signal based on the first measurementvalue, wherein the second temperature controller is further configuredto generate the second feedback temperature control signal based on thesecond measurement value, and wherein the third temperature controlleris further configured to generate the third feedback temperature controlsignal based on the third measurement value.
 13. The wafer processingapparatus of claim 12, wherein the first power supply is configured toprovide operational power to a central portion of the heatercorresponding to the central region, based on the first feedbacktemperature control signal, wherein the second power supply isconfigured to provide operational power to an edge portion of the heatercorresponding to the edge region, based on the second feedbacktemperature control signal, and wherein the third power supply isconfigured to provide operational power to a middle portion of theheater corresponding to the middle region, based on the third feedbacktemperature control signal.
 14. The wafer processing apparatus of claim11, wherein the wafer chucking controller is further configured toidentify a distance between the heating plate and a certain location ofa wafer disposed on the heating plate based on the first feedbacktemperature control signal, the second feedback temperature controlsignal and the third feedback temperature control signal.
 15. The waferprocessing apparatus of claim 11, wherein the wafer chucking controlleris further configured to identify a three-dimensional shape of the waferbased on the first feedback temperature control signal, the secondfeedback temperature control signal and the third feedback temperaturecontrol signal.
 16. The wafer processing apparatus of claim 15, whereinthe wafer chucking controller is further configured to generate thefirst feedback pressure control signal and the second feedback pressurecontrol signal corresponding to the first electronic pressure regulatorand the second electronic pressure regulator, respectively, based on thethree-dimensional shape.
 17. A wafer processing apparatus comprising: aheating plate through which a plurality of vacuum ports is formed, and acentral region and an edge region surrounding the central region aredefined; a plurality of temperature sensors configured to measure atemperature of the heating plate; a heater configured to heat theheating plate; a first power supply and a second power supply configuredto provide operational power to the heater; a first meter and a secondmeter configured to measure a first power output of the first powersupply and a second power output of the second power supply,respectively; a first temperature controller and a second temperaturecontroller configured to generate a first feedback temperature controlsignal and a second feedback temperature control signal configured tocontrol the first power output and the second power output based onmeasurement values of the plurality of temperature sensors; anelectronic pressure regulator configured to regulate pressure of theplurality of vacuum ports; and a wafer chucking controller configured tocontrol pressure of the electronic pressure regulator, and generate afeedback pressure control signal for controlling the pressure of theelectronic pressure regulator based on the first power output and thesecond power output.
 18. The wafer processing apparatus of claim 17,wherein the wafer chucking controller is further configured to identifya degree of warpage of the wafer based on the first power outputmeasured by the first meter and the second power output measured by thesecond meter, and control the electronic pressure regulator based on thedegree of warpage.
 19. The wafer processing apparatus of claim 18,wherein the wafer chucking controller is further configured to generatethe feedback pressure control signal based on the degree of warpage ofthe wafer.
 20. The wafer processing apparatus of claim 18, wherein thefirst power supply is further configured to provide operational power toa central portion of the heater corresponding to the central region,based on the first feedback temperature control signal, and wherein thesecond power supply is further configured to provide operational powerto an edge portion of the heater corresponding to the edge region, basedon the second feedback temperature control signal.